f you’ve never caught the Blue Man Group live — hard to believe, actually, what with the permanent outposts in seven cities throughout America, plus the perpetual tour — it’s certainly worth seeing. It’s not too far-fetched to call the silent blue gag-sters a populist cultural phenomenon. God knows — what with the food spitting, the paint splashing, and the toilet-paper flinging — no one would ever call them a sophisticated theatrical ensemble. Yet set against a backdrop of powerful live rock music, the trio’s oddball antics and pervasive sense of wonder make for generation-spanning entertainment. And maybe that’s all the reason you need to catch tonight’s 7:30 show at Akron’s E.J. Thomas Hall.